Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems

Title: Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems

Full Record
Other Related Research

Abstract

The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.

Inventors:

Griffiths, Stewart K ^[1]; Nilson, Robert H ^[2]

Danville, CA
Cardiff-by-the-Sea, CA

Issue Date:: 2001-01-01

Research Org.:: SANDIA CORP

OSTI Identifier:: 873908

Patent Number(s):: 6270641

Assignee:: Sandia Corporation (Albuquerque, NM)

DOE Contract Number:: AC04-94AL85000

Resource Type:: Patent

Country of Publication:: United States

Language:: English

Subject:: method; apparatus; reducing; sample; dispersion; junctions; microchannel; systems; performance; devices; improved; providing; wyes; tees; produce; dispersions; traverses; junction; reduced; results; contraction; expansion; regions; reduce; cross-sectional; portion; carefully; designing; geometries; levels; comparable; effects; ordinary; diffusion; numerical; algorithm; employed; evolve; low-dispersion; computing; electric; pressure; field; candidate; configurations; transport; overall; effective; greatly; increase; flexibility; design; permitting; induce; particular; ability; fold; electrophoretic; electrochrornatographic; separation; columns; allow; dramatic; improvements; miniaturization; low-lispersion; particularly; suited; electrochromatographic; separations; pressure-driven; chromatographic; applicable; microfluidic; employing; electroosrnotic; flows; reaction; mixing; dilution; synthesis; sample transport; separation column; particularly suited; chromatographic separation; separation columns; systems employing; electrophoretic separations; channel systems; microfluidic systems; systems employ; greatly increase; electrophoretic separation; separation colum; channel device; /204/422/

Citation Formats


                    Griffiths, Stewart K, and Nilson, Robert H. Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems.  United States: N. p., 2001. 
        Web.

Copy to clipboard


                    Griffiths, Stewart K, & Nilson, Robert H. Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems.  United States.

Copy to clipboard


                    Griffiths, Stewart K, and Nilson, Robert H. Mon .  
        "Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems".  United States.  https://www.osti.gov/servlets/purl/873908.

Copy to clipboard


                    
@article{osti_873908,

  title        = {Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems},

  author       = {Griffiths, Stewart K and Nilson, Robert H},

  abstractNote = {The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2001},

  month        = {1}

}

Copy to clipboard

Patent:

View Patent

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE Patents and OSTI.GOV collections:

Method And Apparatus For Reducing Sample Dispersion In Turns And Junctions Of Micro-Channel Systems

Patent Griffiths, Stewart K. (Danville, CA), Nilson, Robert H. (Cardiff-by-the-Sea, CA)

What is disclosed pertains to improvement in the performance of microchannel devices by providing turns, wyes, tees, and other junctions that produce little dispersion of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. The low dispersion features are particularly suited for microfluidic devices and systems using either electromotive force, pressure, or combinationsmore »« less
Full Text Available
Apparatus for producing a thin sample band in a microchannel system

Patent Griffiths, Stewart K [Livermore, CA]; Nilson, Robert H [Cardiff, CA]

The present invention improves the performance of microchannel systems for chemical and biological synthesis and analysis by providing a method and apparatus for producing a thin band of a species sample. Thin sample bands improve the resolution of microchannel separation processes, as well as many other processes requiring precise control of sample size and volume. The new method comprises a series of steps in which a species sample is manipulated by controlled transport through a junction formed at the intersection of four or more channels. A sample is first inserted into the end of one of these channels in themore »« less
Full Text Available
Microchannel apparatus comprising plural microchannels and methods of conducting unit operations

Patent Wegeng, Robert S [Richland, WA]; TeGrotenhuis, Ward E [Kennewick, WA]; Whyatt, Greg A [West Richland, WA]

Microchannel apparatus comprising a header and plural flow microchannels is described in which orifices connect the header and the flow microchannels. The orifices constrict flow. The ratio of the cross-sectional area of each of the orifices to the cross-sectional area of the flow microchannels connected to the orifices is between 0.0005 and 0.1. Also described is microchannel apparatus for conducting unit operations in which a device comprises two arrays of microchannels, and a unit operation is conducted on a fluid as it passes through the first set of microchannels and into a header where a second unit operation is performed,more »« less
Full Text Available
Apparatus and method for reducing inductive coupling between levitation and drive coils within a magnetic propulsion system

Patent Post, Richard F [Walnut Creek, CA]

An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitationmore »« less
Full Text Available
Method and apparatus for reducing diffraction-induced damage in high power laser amplifier systems

Patent Campillo, Anthony J [Los Alamos, NM]; Newnam, Brian E [Los Alamos, NM]; Shapiro, Stanley L [Los Alamos, NM]; ...

Self-focusing damage caused by diffraction in laser amplifier systems may be minimized by appropriately tailoring the input optical beam profile by passing the beam through an aperture having a uniform high optical transmission within a particular radius r.sub.o and a transmission which drops gradually to a low value at greater radii. Apertures having the desired transmission characteristics may readily be manufactured by exposing high resolution photographic films and plates to a diffuse, disk-shaped light source and mask arrangement.
Full Text Available

Similar Records